This invention relates to the centering of well blocks in steelmaking vessels, and in particular, it relates to a well block centering tool for aligning well blocks within steelmaking vessels either during their initial construction or during the relining of the vessel. Steelmaking vessels, such as ladles, include discharge bores through which molten metal is discharged. The discharge bores are located within well areas which include an outer steel shell made up of a level plate and a mounting plate, and an inner refractory lining including a well block. The discharge bore extends through the level plate and mounting plate and is coaxially aligned with the centerline of the well area of the ladle. The mounting plate provides means for attaching a slide gate valve to control the flow of molten metal being discharged through the bore.
The well block also includes a discharge bore. This bore is adapted to receive a nozzle insert which is mortared in place within the well block. The nozzle insert extends downward through both the level and mounting plates and engages the mechanism of the slide gate.
Therefore, the well block must be accurately aligned with the centerline of the discharge bore in order to properly seat and align the various parts of the nozzle mechanism. It must also be held in place to insure that it doesn't move out of alignment during the relining of the vessel. This is difficult for workers to accomplish because placement of the well block within the well area obscures their view of the discharge bore located below the well block.
Failure to coaxially align the well block with the well area will cause premature failure of the nozzle parts. In the worse case scenario, the off-center well block can be misaligned to a point where no gap is provided for a mortar joint between a portion of the nozzle insert and the adjacent bore wall of the well block. This scenario also produces a much too large mortar joint between the opposite side of the nozzle insert and the well block bore.
Such substandard mortar joints usually contain voids or gaps which set up conditions whereby molten steel seeps between the nozzle insert and well block causing premature nozzle failure, damage to the slag sensors adjacent the discharge nozzle, and damage to the slide gate mechanism. In addition, the off-center well block can cause misalignment between the nozzle insert and slide gate valve mechanism resulting in unsatisfactory operation of the slide gate valve as the molten steel is discharged from the ladle.